The present invention relates generally to a water screen and particularly to a water screen providing a variable filtration function.
In general, prior to the present invention, water screens have been complicated in nature and have required a great expense of time and money in their manufacture. For example, the L. B. Foster Company, 415 Holiday Drive, Pittsburgh, Pa. 15220 has recently announced, in an advertising brochure, the development of special tooling for cutting slots in well casing for use as water well screens. Additionally, previous water screens do not readily provide for variable filtration. That is, previous water screens are capable of filtering certain size particles from the water as the water flows through the screen, however, in instances wherein the particulate size is less than screen openings, these particles traveled unhindered through the screen and hence remain as contaminants in the water. Thus, in order to filter substantially all sizes of particulate matter, it has often been necessary to utilize additional filtration systems that increase the time and expense necessary to provide filtered water.